There is a need for connection arrangements or mechanisms which securely connect plastic members or parts to other parts without exerting high pressures on the plastic parts. One area where such a need exists is connecting members, such as blower wheels for example, to rotatable drive shafts.
Many plastic materials are subject to a phenomenon called "cold flow." That is, when subjected to pressure, the material will very slowly flow or deform to relieve the pressure. As an example, when a typical clamp is used to secure a plastic blower wheel to a rotatable drive shaft, the material of the wheel flows or creeps over a period of time and the connection becomes loose.
An object of the present invention is to provide an improved arrangement for connecting a plastic member to an elongated shaft.
Another object of the present invention is to provide such a connection arrangement which is not subject to loosening with the passage of time.
Yet another object of the present invention is to provide such a connection arrangement which substantially overcomes problems associated with cold flow of the plastic material.
In accordance with one form of the present invention there is provided a connection arrangement including a rotatable shaft, having a generally cylindrical configuration, and a plastic member. The plastic member has an elongated, generally annular bore fitting around the shaft and a longitudinally extending recess projecting radially outward of the shaft. A locking sleeve fits within the bore and around the shaft. The sleeve has an outwardly extending bight portion received within the recess. At least the bight portion is split to include first and second longitudinally separated portions. Attaching means draws the first and second portions together for securing the locking sleeve and plastic member to the shaft.